How Gut Bacteria Affects the Brain and Body



Don’t you just love a good infographic?

This one shows the mounting research that suggests the bacteria living in our gut can play a significant role in our overall health.

Have you ever wondered what it would be like to go beyond the infographic though?

That's exactly what happened to me when I donned my special research specs and did a "Sherlock Holmes" into some of the research currently out there in cyberspace.

I've looked into each area of the brain and body on the graphic to see how gut bacteria may exert an influence over almost every aspect of our health.

Did you know that it’s estimated that our bodies are composed of ten times more bacteria than human cells, with the gut being home to the largest number of bacteria in the body?

It seems that each day there’s a new study emerging showing just how crucial a role the bacteria living in our digestive tract has on influencing our overall health and wellbeing.

Several not only physical, but also psychological, conditions have been linked to an imbalance in our gut flora, with many of our diets comprising of processed, high-sugar and nutrient-poor foods, it’s not hard to see why.  

Anxiety & Depression

In 2014, the U.S. National Institute of Mental Health spent over $1 million on new research aimed at better understanding the gut bacteria-brain link. Recently, evidence has mounted from studies in mice that the gut micro biome can influence neural development, brain chemistry and a wide range of behaviors, including emotional behavior, pain perception and how the stress system responds.

Mice found to be lacking a certain bacteria in their gut were actually found to be more anxious and less animated, exhibiting depressive-like symptoms.

If you have been struggling with anxiety and depression, speaking with a licensed therapist (like those at BetterHelp) or a naturopathic doctor in Phoenix can also help you improve your mood levels.

Diet also plays an important part. Some foods make us feel calmer while other foods can act as stimulants. Tryptophan can have a positive effect on stress and depression because this amino acid helps your brain produce feel-good chemicals (such as the neurotransmitter Serotonin), making you feel calmer and improving mood levels.

Tryptophan-rich foods may also improve sleep, thereby promoting overall mental wellbeing. Some tryptophan-rich foods include: turkey, chicken, bananas, milk, oats, cheese, soy, nuts, peanut butter, and sesame seeds. Click here to get the recipe for my tryptophan-rich Garlic & Rosemary Chicken


Many neurologists now believe that Parkinson’s disease may start in the gut.

Specifically, untreated Helicobacter Pylori (a type of bacteria that, if left untreated, can live in the gut and cause a range of complications such as ulcers in the stomach lining) has been linked to later development of Parkinson’s disease, although conclusive evidence is lacking.

Helicobacter Pylori may also affect the absorption of Parkinson’s disease medications, and consequently affect the overall response to treatment.

There are also many gastrointestinal symptoms such as constipation that occur as prominent features of Parkinson’s disease. Including foods high in dietary fibre, such as fresh fruits, vegetables, and whole grains is important in the overall treatment of Parkinson’s disease.

As medications for Parkinson’s often cause nausea, it may also be wise to incorporate foods known to reduce symptoms of nausea, such as ginger, tonic water and high protein snacks before bedtime. Try my high protein, Baked Salmon with Garlic and Ginger recipe. It’s high in Omega-3 fatty acids, which is great for brain health too.


New evidence exists suggesting that gut bacteria alter the way we store fat, and how we respond to hormones that make us feel full or hungry. It appears that the wrong mix of microbes may set the stage for obesity and diabetes from birth.

Researchers are now investigating ways in which they may create baby formulas and/or supplements that will promote virtuous microbes while suppressing the harmful types.

When promoting healthy gut bacteria, it’s important to eat a clean diet that includes minimal amounts of processed foods, plenty of fresh fruits and vegetables, and fermented foods such as kim chi, tamari, tempeh, yoghurt and sauerkraut.

Drinking plenty of water and remaining hydrated is also important; as this helps the body flush out any toxins. Green Juices are an excellent way to detox while hydrating the body, and ensuring you are still getting plenty of nutrients.

Colon Cancer

In any population of living organisms, some are helpful to digestion while others go rogue and turn cells cancerous. Scientists now know that patients with colon cancer harbor different microbial communities in their digestive tract than those without the disease.When mice with colon cancer were given antibiotics to control their bacterial populations, they developed fewer and smaller tumors than those who didn’t receive the bacteria-fighting medications.

As excessive consumption of red meat and alcohol are known risk factors for the development of colon cancer, if you have a history in your family (genetic predisposition is also a risk factor), it may be wise to also include more vegetable based meals in your diet.

These meals also tend to be higher in dietary fibre, which is known to promote colon health. There are many vegetarian recipes to choose from on my website, such as this delicious Simple Oven Roasted Vegetable dish.

Rheumatoid Arthritis

Your gut microbe plays a major role in your immune system, constantly protecting you from illness, which you may never actually become unaware of.

Autoimmune disorders, including rheumatoid arthritis and lupus, have long been thought to have a genetic component that is triggered by microorganisms, specifically, by increased levels of the bacteria Prevotella copri.

Inflammation in the body, leaky gut syndrome and other gastrointestinal problems could also trigger flare-ups, particularly symptoms of painful inflammation, in diseases like Rheumatoid Arthritis, lupus, and multiple sclerosis. Read about my favourite six ingredients to lower inflammation naturally here.


As is the case with most mental illness, the cause of schizophrenia remains unknown. However, a lack of normal gut bacteria has been linked with changes in brain development, potentially contributing to the cause or at the least worsening the symptoms.

The conventional treatment for schizophrenia is usually long-term use of antipsychotic medication. The incidence of blood sugar problems and diabetes is also much higher in those with schizophrenia.

A person’s intake of sugar, refined carbohydrates, caffeine, alcohol and cigarettes, as well as stimulant drugs, all affect the body’s ability to keep blood sugar level balanced.

The fact that common antipsychotic medication may also further disturb blood sugar control means that simple nutritional alterations, like choosing foods that have a low glycemic index (GI) that will not spike blood sugar levels, can work alongside a conventional treatment approach to Schizophrenia.

Foods low in GI include legumes, eggs, sweet potato, fruits such as oranges and whole grains such as oats. Try this Green breakfast bowl for a low GI breakfast option.


Research has suggested that many children with autism have abnormal digestive bacteria in their intestines. Some of these studies have associated specific types of gut bacteria with more-severe autism symptoms.

Many autistic children have received repeated or prolonged courses of antibiotic drugs for ear or other respiratory infections during their first year, before the diagnosis of autism. Broad-spectrum antibiotics kill good as well as bad bacteria in the gut, and this may be why autistic children commonly suffer bowel irregularities.

For this reason, it is important to include probiotic-rich foods, such as yoghurt in to restore the balance of good bacteria after anti-biotic treatment. Try my yoghurt berry crunch pot a sugar-free snack kids are sure to love!

Irritable Bowel Syndrome

There is now plenty of evidence to support the idea that disturbances in the gut bacteria play a role in at least some people with irritable bowel syndrome (IBS).

Antibiotic use, which is known to disturb the gut flora, may predispose individuals to IBS. Others may develop IBS suddenly after an episode of stomach or intestinal infection (gastroenteritis) caused by bacteria.

Inflammation may also be present in the bowel wall of some IBS patients, which could be a result of abnormal bacteria in the gut. Altering the bacteria in the gut, through regular consumption of probiotic-rich foods and temporary supplementation has been shown to improve symptoms in IBS sufferers.

 The good news is that a few simple dietary changes can drastically help with restoring the balance of good bacteria in your gut. If you feel some of your health concerns may be due to an imbalance in your digestive bacteria, then it may be worthwhile looking into my Heal Your Gut program.

This is a four week online program that will restore your inner health so that you can experience wellness from head to toe, gain more energy and vitality and feel healthy again. The next program starts on 7th September 2015.

7 Responses to “How Gut Bacteria Affects the Brain and Body”

  1. Adam Trainor says:

    I do love a good infographic. Helps to give you a better understanding of things, and this one definitely does. So after reading this post the majority of most health problems are related to bacteria being in the gut. I can understand bowel related health problems such as IBS and crohns diseas e accuring from bacteria being in the gut but the others not so much. Is there a way to manager or clear out this bacteria in the gut?

    • lee says:

      I agree. Yes there is a way to rebalance the gut. There’s a lot of info about how to do it step by step in my Heal Your Gut Book.

  2. Adam Trainor says:

    Great thanks Lee, I will take a look at that.

  3. gaye chapman says:

    Hi Lee, do you think diet and natural remedies can completely eradicate Helibactor Pylori please? Gaye

  4. Jessica says:

    Would you suggest taking your love your gut powder for helibacter pylori as opposed to dr recommended antibiotics, etc? How long would you need to take it, and what dosage?

    • Lee says:

      Hello, I recommend the Love your gut powder and the love your gut Synbiotic which will help the infection, take them for 6 weeks and then do another test. Lee

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